class Solution {
public:
    int countCompleteDayPairs(vector<int>& hours)
    {
        int ans = 0;
        for (int i = 0; i < hours.size(); i++)
            for (int j = i + 1; j < hours.size(); j++)
                if ((hours[i] + hours[j]) % 24 == 0)
                    ans++;
        return ans;
    }
};